PMDC motors are well-known and have many uses. A PMDC motor generally comprises a stator and a rotor. The stator comprises a housing, permanent magnets fixed onto an inner surface of the housing and an end cap closing an open end of the housing. The rotor comprises: a shaft, a rotor core fixed onto the shaft, a commutator fixed onto the shaft adjacent one end of the rotor core and windings wound about teeth of the rotor core and terminated on segments of the commutator. The rotor is mounted with the rotor core confronting the permanent magnets and with the shaft rotatably supported by a bearing held by the end cap. Brushes are supported by one of the end caps. The brushes make sliding contact with the segments of the commutator to supply power to the windings.
FIG. 10 shows an end cap of a prior art PMDC motor. The end cap comprises two brushes 13 and 23, two chokes 15 and 25 and two terminals (only one terminal 19 is visible) for connecting to a power source. The brush 13, the choke 15 and the terminal 17 are connected in series. The brush 23, the choke 25 and the other terminal are connected in series. The brushes and the chokes are laid on an inner end surface of the end cap, resulting in that there is not enough space left for mounting other components such as electromagnetic compatibility (EMC) components and overcurrent protection components. One solution is to mount the EMC components and overcurrent protection components outside of the motor. However, performance of the components is reduced because the components are farther away from the armature windings.
Thus it is desirable to develop a small PMDC motor having an end cap that have enough space for mounting overcurrent protection component and/or other EMC components.